%YAML 1.2
---
!!map { 
  ? !!str "american" 
  : !!seq [ 
        !!str "Boston Red Sox", 
        !!str "Detroit Tigers", 
        !!str "New York Yankees" 
    ],
  ? !!str "national"
  : !!seq [
        !!str "New York Mets",
        !!str "Chicago Cubs",
        !!str "Atlanta Braves",
    ],
  }